Silicone resins can be used under high temperatures of over 200.degree. C. They also have good chemical resistance. Their gas permeability is also extremely high, their electrical characteristics are excellent, and they also have excellent biocompatibility.
In general, when a silicone resin is bonded to another material, the only option is to bond it using a silicone-based adhesive agent. However, silicone-based adhesive agents are not universally applicable, e.g., they have extremely poor compatibility with urethane resins and vinyl chloride-based resins, resulting in poor adhesive strength. A low-temperature plasma treatment step, or a primer treatment can be performed, or some other method employed, to augment adhesive strength, but satisfactory adhesive strength has still yet to be obtained.
Furthermore, silicone resins have good release properties; but because of that, bonding a silicone resin with another plastic, with an adhesive not based on a silicone resin, or coating a silicone resin with another resin, is extremely difficult.
Methods for compounding silicone composition have therefor been proposed; however, the compounding conditions vary depending on the resin being compounded and other factors, and an inordinate number of steps is required.